The government must ensure that any sale of A123'stechnology, which has also been used by the military and tosupport the U.S. electrical grid, does not threaten domesticsecurity, the senators said in letter to Treasury SecretaryTimothy Geithner, Energy Secretary Steven Chu and other topcabinet officials.

Among the eight senators and one senator-elect signing theletter were influential Republican Rob Portman of Ohio andDemocrat Dick Durbin of Illinois.

They called on the powerful Committee on Foreign Investmentin the United States (CFIUS) to consider any "potentiallyharmful consequences that could occur as a result" of a sale toWanxiang.

Wanxiang's law firm Sidley Austin has said that it wouldsubmit its bid to CFIUS.

The lawmakers also raised concerns that Wanxiang couldreceive taxpayer funded assets from A123, which was awarded a$249 million grant by the Obama administration.

"The transfer of assets, technology and intellectualproperty, developed with American tax dollars, to a foreigncompany would be irresponsible," the letter said.

The U.S. government has argued in court that A123 cannot besold without its consent since it received a grant from theEnergy Department.

The government did not identify a preferred buyer in itscourt filing, but the administration has stressed that none ofthe government's grant would be allowed to fund facilitiesabroad.

Prior to filing for bankruptcy in October, A123 had receivedabout half of its grant.

When the company filed for Chapter 11 bankruptcy protectionin October its plan was to sell its battery business toMilwaukee-based Johnson Controls for $125 million.

This planned sale is subject to better bids at an auction inDecember. Wanxiang, an auto parts supplier, has said it intendsto make an offer for the company.

Wanxiang's pursuit of A123 has been met with uneasiness fromCongress. Other lawmakers such as Republican Senators John Thuneand Charles Grassley and Democratic Senators Debbie Stabenow andCarl Levin have already voiced misgivings.